Rear tire width requirements in relation to HP?

Oops, I meant 425-450 hp :-) not 235-250!!! Lol...
OOps is right.
With skinny tires and Hemi springs, on the street you should be fine.
But,you are gonna need more rubber. And then you might, that's might, need an aftermarket adjustable snubber.
I have one on my 425 hp, but I've only ever used it twice, since 1999;both times, at the track.